Fractures and Dislocations

Question 1

What are the four stages of fracture repair?

Answer 1

1. Inflammation
2. Soft callus
3. Hard callus
4. Bone remodelling

Question 2

Describe the first stage of fracture healing

Answer 2

Inflammation:

• haematoma and fibrin clot form
• platelets are the biggest drivers of inflammatory process in bone but PMNs, neutrophils, monocytes and macrophages are also involved.
• fibroblasts, mesenchymal and osteoprogenitor cells are also involved
• angiogenesis occurs; microphages produce angiogenic factors under hypoxic conditions

Question 3

Describe the second stage of fracture healing

Answer 3

Soft callus:

• begins when pain and swelling subside
• lasts until bony fragments are united by cartilage or fibrous tissue
• provides some stability of fracture while waiting for hard callus to form
• angulation (bending) can still occur, but the bone cannot shorten or rotate
• angiogenesis continues

Question 4

Describe the third stage of fracture healing

Answer 4

Hard callus:

• cartilage is converted to woven bone
  
  • woven bone fibres are orientated in all different directions
• bone is “healed” but is still weak

Question 5

Describe the fourth stage of fracture healing

Answer 5

Bone remodelling:

• woven bone is converted to lamellar bone
• hard callus is not efficient (is too heavy); bondee is remodelled to be lighter and more efficient
• medullary canal is reconstituted
• bone responds to loading characteristics

Question 6

Define “dislocation” and “subluxation”

Answer 6

Dislocation = complete joint disruption, no contact between articular surfaces
Subluxation = partial dislocation; not fully out of joint, still some contact between articulation but there is "wrong contact" and therefore the joint does not articulate properly

Question 7

Define an open fracture

Answer 7

There is a direct communication between the external environment and the fracture.

Question 8

How would you describe the shape of a fracture?

Answer 8

Transverse
Oblique
Spiral
Complex

Question 9

What is “comminution” of a fracture? How is this classified?

Answer 9

Comminuted fractures: fractures where more than 2 bone components are created
Classification:
 - none
 - butterfly
 - segmental
 - bone loss
 - grade +, ++, +++

Question 10

What types of deformity can be caused by a fracture?

Answer 10

Displacement
Angulation
Rotation
Axial deformity

Question 11

Give four causes of pathological fractures

Answer 11

Osteoporosis
Cancer
Bone infection
Bone cysts

Question 12

Give some risk factors for stress fractures

Answer 12

Runners; changes in workout type/intensity
Cavus foot (high arches)
Poor footwear 
Osteoporosis 
Muscle weakness
Inflexibility
Joint laxity
Bone malalignment
Limb asymmetries
Previous injury
Training errors
Environmental conditions

Question 13

Which bones are most commonly affected by stress fractures?

Answer 13

Metatarsal shafts (2nd metatarsal especially)
Proximal femur
Tibia

Question 14

Give four major components of sports injury management

Answer 14

RICE (rest, ice, compression, elevation)
Analgesics
Cross-training
Gradual return to activity

Question 15

Define “dislocation”

Answer 15

complete joint disruption; bones have become completely separated from each other

Question 16

Define “subluxation”

Answer 16

partial joint disruption; bones are only partly out of position

Question 17

Describe the possible shoulder dislocations and their associated deformities. Which is more common?

Answer 17

Anterior dislocation: squared off appearance
Posterior dislocation: locked in internal rotation
Inferior dislocation: arm appears to be permanently held upward or behind the head

Anterior dislocation is by far the most common. Inferior dislocation is least common (<1% of cases) but carries the greatest risk of damage to neurovascular structures